Educational appliance.



E'. N. TUCKEY.

EDUCATIONAL APPLIANCE.

APPLICATION FILED OCT. I, I9I3. 1,294,089. Pamed Nov. 7, 1916.

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EDUCATIONAL APPLIANCE.

APPLICATION FILED 00T. I.I9I3.

Patented Nov. 7, 1916.

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TTORNEY.

Patented Nov. 7, 1916.

4 SHEETS-SHEET 3 t. L h

E. N. TUCKEY.

EDUCATIONAL APPLIANCE.

APPucATxoN FILED ocT.1. 1913.

E.I\1 .TUCKEYK EDUCATIONAL, APPLIANCES.

APPLICATION FiLED OCT.

1, 1913- Pateted NOV, 7, 1916.

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EDUCATIONAL APPLIANCE.

specification of Letters Patent.

Application led October 1, 1918. Serial No. 792,891.

ments in educational appliances as a mediuml of instruction in thescience of economics, includin'gthe production, exchange, distributionand use of wealth and the various forces which tend to influence orfluctuate commercial prices and-standard values.` L

It is generally recognized that the fundamental relations existingbetween the various factors of commerce, such as demand, supply,marginal costs, values and prices of goods and gold, and also betweensuc-h fac! tors and the numerous forces or agencies which tend toaffecter iniiuence them,are not easily comprehended and are only vaguelyunderstood except by educators and experts in this science and thatunder the present more or less abstract methods of instruction, thestudent iinds it extremely diiiicult, without laborious andtime-consuming effort, to fix in mind such relations or to properlyapply the various forces to the particular commercial factor or factorswhich they affect. This condition is largely due to the widelydiversified and complex nature of such forces and to the factthat therelations between the various commercial factors and forces whichinfluence them are continually shifting which tends to confuse the mindand to render the science seemingly indefinite, theoretical andimpracticable, but I have found that these forces maybe deiinitelycorrelated to their respective factors and exhibited in their properrelations thereto in such manner as to produce inthe mind ofthe studenta comprehensive and lasting impression of the fundamental principles ofeconomics after a comparatively short period of study and withoutexcessive effort on the part of the instructor.

The main object, therefore, is to stimulate andA encourage a moreintelligent and universal study of this' science and its practicalapplication to comercial interests through the medium of a simple,practical and easily manipulated mechanical appliance by which thevarious factors of commerce and the numerous forces which tend vtoinfluence them may be brought into or represented as a unitarycomblnation or association in their proper relations, whereby thestudent may see at a glance and readily comprehend the full scope andmeaning'of such relations and be able to determine approximately theresult iof the. application of any particular force or forces to anypredetermined commercial factor or factors which might be iniiuencedthereby.

In other words, I have sought to exhibit, mechanically, through-themedium of sliding scales f values, the causal, quantitative andfunctional relations existing between particular prices, costs, generalprice levels,

purchasing power of gold, demand and suplply of both goods and gold, andthe multitudincus `forces aii'ecting these factors and also in turnaffected by them.

Other objects and uses relating to specific parts of the apparatus willbe brought out 1n the following description'.

In the drawings-Figures 1 and 2 are respectively a front elevation and arear elevation of an apparatus embodying the various featuresof myinvention. Fig. 3 is a transverse vertical sectional view of the sameapparatus taken on line 3-3,Fig. 2. Figs. 4,5, 6 and 7`are enlargedtransverse horizontal sectional views taken respectively on lines 4 4',5 4), 6 6 and 7 7, Fig. 2. Fig. e is an enlarged sectional View of theclamp for frictionally locking the upright center bars together. Figs. 9and 10 are diagrammatic views showing respectively the cord or cableconnections between the goods-bar, price pointers, and gold-value barand the cable connections between the gold-bar, ,gold-value pointers andprice bar.

The entire apparatus is easily portable as a unitary structure and, asillustrated, comprises a suitable supporting base 1- carrying aplurality of, in this instance three, upright scale-bars Q-d, -3- and-4- which are arranged side by side uniform distances apart and inparallelism and are rigidly connected at the bottom and top byhorizontal cross bars -5- and -6- for holding themin fixed relation,thereby con# Patented Nov. 7, raie.

The apparatus may, therefore, be conveniently positioned u on the floorof a class room or other locahty between the instructor and students sothat one side, designated as the front, faces the class while theopposite side or back faces the instructor thus permitting suchinstructor to face the stu# dents and to manipulate the various parts ofthe apparatus in 'illustrating any particular principle of economicswhich may be under discussion. These u right bars -2-, -3-, and -4.- arepre erably of uniform vheight and extend a considerable distance abovethe base to afford ample clearance for the vertical adjustment of theparts which are movable along the upright bars between the cross bars 5and 6, each of said bars being provided on each of its front and rearfaces with separate vertical scales having their graduations spaceduniform distances apart and numbered in progressively increasing valuesfrom bottom to top so that like numbers will be approximately inhorizontal alinenient. In this particular instance, the numerals of onescale of eachbar progressively increase in value by units from 1 to 20while those of the other scale progressively increase in value in therelation of 1, 4, 7 and so on to 58, thereby extending the range ofusefulness of the same device as will be hereinafter more fully ex?plained, the different scales on the same side of the bar beingdistinguished 'from each other either by color, size or Style, thevalues of one scale alternating with .those of the other scale.

The scales on the bars 2 and -3- represent variations in quantitativevalues of demand and supply, said bars being designated respectively bythe abbrevations D and ".S printed or otherwise impressed on the frontand rear faces of the opposite ends thereof or upon the adjacentportions of the cross bars -5- and -6-.

The scales on the upright bars are preferably printed on both sidesthereof in the' same relation so that the instructor stand ing back ofthe apparatus may readily determine the position of the adjustable partsby the 'same readings as appear to the class in front.

In the preferred form of my invention,-

the scale or graduations when used on the' middle bar 4- are the sameand num- I bered in the same order as those on the bars and --,rbut maybe omitted and scribed and is held in itsV adjusted position hby afriction clamp --39"', Fig. Ai3. The

-costs or marginal costs of both goods and gold and this bar may,therefore, be

termed a cost or marginal cost bar for illustratin the relation betweensuch costs and the prlces of goods'and value of gold.

In this connection it may be stated that if 011e seeks merely to readthe equilibration of demand-quantities and supply-quantities and ofdemand-prices and supply-prices of both goods and gold in terms of eachother in an exchange, it is`unnecessary to use the marginal cost-bar, itbeingunderstood than any past cost of production of a commodity doesvnot affect its present price, except as it infiuences the estimate offuture costs, the minds of the buyers 4and sellers and consequently thedemand and supply. But the theory is that under strictly ideal co-mpeti-1 tive conditions the output and supply of goods will be increaseduntil, on the average or in general, the latter equals thequantity-demand at a price that is equal to market cost (including incost the competitive rate of profits). In Fig. l, however, the pricesindicated are above -the'cost, the former being 1.40 and the latter1.80.

For convenience, the apparatus is supplied with the double cost-bars -4-and l-, the bar 4'- being arranged to slidealong the lower one and to beheld in place by a clamp, as -39-. It is evident, however, that thestationary cost-bar Jiwould be suilicient with means to indicate thefigure on the cost-scale representing the marginal cost.

By arbitrarily adjusting the scale-bar -4 the price-pointers can be usedto indicate the cost as well as the prices so that having provided thedouble cost-bar and slide-indicator, the apparatus affords three methodsof indicating the cost for comparison with the prices resulting from theequilibration of demand and supply, the adjustment of the cost-bar orindicator being made either before or after the equilibration of theother parts. Furthermore, thecost of both goods and gold may beindicated on the apparatus at the same time by either one of two methodsz-frst-by using two slideindicators on the stationary cost-bar -'4-;second-by using the sliding cost-bar 4'- and one clasp-indicator. Inthe' latter case the price-pointers would also serve to indicate one ofthe costs.

If it is desired to indicate by means of the apparatus the effect uponprices of a change in a force operating upon the demand or. supply 'ofgoods or gold, the apparatus including the cost-bar -4- (orcost-indicators) would be adjusted to represent the conditions of cost,demand, supply, etc. Having indicated on a force-card the degree inchange of the force in question, the effect of that change upon thecostquantity, the demand-quantity, the supplyprice, the demand-price orthe exchangeprice ofboth goods or gold, or upon all of the'above-namedelements combined would be shown by raising or lowering, as the case Vsoas to move vertically in the same plane Y as and between the stationarybars and are guided in suitable ways in the upper cross bar -6 as shownin Fig. 4. These bars -Q- and -9- are designated respectively as a pricebar and a gold value bar and are accordingly represented by theabbreviations 1). and Gn V. printed 0r otherwise impressed thereon orupon the adjacent portions Aof the main frame in alinement therewith,the price bar. 8- being provided on its front face with separate scalessimilar to those on 'the stationary bars 2 and 3 While the gold-valuebar is also provided with separate scales having their graduationsalternating with each other, but designated by numerals which are thereciprocals of those on the price bar inversely arranged;that is thenumerical values .1, .1, .4, .2, .7, 3, 1.0, etc., reading from thebottom upon the pricebar -8- have their reciprocals 10. 10. 2.5, 5.,1.4, 3.3, 1.0, etc., reading from the top downward on thev scale-bar -9.

It, therefore, follows that if the graduations and correspondingnumerals of both bars are similarly spaced and the. numeral of 011e barand its reciprocal on the other bar are registered with predeterminedpoints;

the simultaneous movement of both bars the same distance in reversedirections or the similar reverse movement of the points will givereadings of diflerent price numerals and their reciprocal gold valuenumerals and vice versa for the reaso'n that the purchasing power ofgold is the reciprocal of the general level of prices.

To facilitate operation the reciprocals of the various numerals on eachsliding bar are printed or otherwise impressed on the edges thereof inline withthe corresponding numerals so that they may be easily read bythe operator particularly when adjusting the` apparatus for use.

The fundamental law of the effect of fluctuations in quantitative valuesor demand-and supply of both goods and gold above or below apredetermined level upon the prices and marginal costs of goods or uponthe value of gold is more or less generally understood or may be easilyexplained by means of the scale bars and suitable pointers properlyadjusted along said bars. For example, an increase orl decrease in thesupply of any particular kind of goods or commodity above or below apredetermined level produces a corresponding decrease or increase in theprice of-such commodity while on the other ,hand any increase ordecrease in the demand of a commodity above or below a predeterminedlevel produces a corresponding increase` or decrease in the price ofthat commodity and, While these relations between quantitative valuesand prices of goods or commodities may be clearly pointed out on thescale bars, I prefer to illustrate these relations automatically and forthis purpose have provided the apparatus with afloating cross bar -10-extending transversely across and at the back of the upright scale barsand some distance beyond the outer edges of the frame bars -2- and -3-for receiving and supporting separately movable disks -1land -12---having their inner edges provided with pointers 13- and -14- movablealong and in proximity to the edges of the stationary scale bars -2- '3-to register with any of the graduations thereon, thereby indicating anylevel or variations in quantitative values as the floating bar 10 oreither end thereof is adjusted vertically. This floating bar may bedesignated as the goods bar and for this purpose bears the word Goods 7printed or otherwise impressed on at least the front side thereof so asto be visible to the students while the disks -lland l2-- and theirpointers -13- and 14.- may be designated respectively as the demand diskand pointer and supply disk and pointer, said disks `bearing theabbreviations D. and S. printed or otherwise impressed upon their frontfaces to distinguish one from the other, the demand disk h11- and itspointer -13- being movable along the demand scale bar -2- whilefthe suply disk and its pointer -14- are movabe along the supply scale bar -3-.

The goods bar -10 is centrally fulcrumed or pivoted at -15- to avertically movable cross head or frame ,16- which is slidable along andguided upon the intermediate scale bar and adjacent sliding scale bars-8- and ,-9- and also forms an additional guide for the verticallvmovable scale bars. 'l

The object of pivoting the goods bar -lO- to the cross head -16- is topermit said bar to rock or tilt vertically for the purpose of moving thedisks 11- and -12- and their pointers -13- and 14- along theirrespective, scale bars --2- and -3- and thereby indicating quantitativeat -17- and -18- to the adjacent endsof the goods bar l0- andare'counterweighted by suitable weights -19- to hold the disks and theirpointers in horizontal position as the bar 10 is tilted vertically ineither direction. y

The floating bar `10 is supported and manipulated by suitable cords orcables 20- and -21- passing over separate sets of sheaves Q2-f and 23 onthe top cross bar -6-'- and having their outer ends attached to thecorresponding ends of the ybar at points near the plvots of theirrespective disks -11- and l2- and their opposite ends suspended somedistance below the upper cross bar near the center o the apparatusandwithin easy reaching distance of the operator where they may bemanipulated at will to raise and lower either end of the goods bar andthe corresponding disks and pointers, the inner sheaves -22- and '-23-being preferably of the gripping t pe to hold the cords and partscarried thereby in their adjusted positions. It is now evident that thegoods bar -10- may be adjusted by means of the cords 20 and 2l along thescale bars -2- and -3` t'o any predetermined level or tiltedl todifferent angles withincertain limits and that by operating the one cordand not the other the adjacent end of the bar and corresponding disk andpointer may be raised or lowered without materially changing theposition of the other end of the bar and adjacent disk and pointer tobring such first-named pointer to any predetermined graduation on theadjacent stationary scale bar.

Associated with the goods-bar-lO- and its demand and supply pointers-13- and 1lare separate price pointers Q4- and -25- which are mountedrespectively upon sliding heads '-26- and -27, the latter being movablelengthwise of and upon their respective demand and supply bars 2 and -3-to shift4 the pointers 2liand -25- along the graduations on the movableprice 'bar -8- with which the pointers are adapted to register. Theseprice pointers are adapted to move simultaneously with the verticaladjustment of their corresponding demand `and supply disks -11- and l2-to show the effect 011 prices indicated by the price bar as a' result ofvariations in either demand or supply from a predetermined level towhich ythe goods-'bar 1s normally set and for this near rits lpoint ofconnection with the demand di 11-.v That is, one end of this cable isconnected, at the point specied, to the goods-bar and then passesdownwardly around a sheave -31- on the upper edge of the `bottom crossbar 5- and thence upwardly around a sheave 32- on the under side of theupper cross bar -6- and thence downwardly to the slide -26- so that themovement of the demand end of the goods-bar and its pointer 13 lineither direction alongi the upright scale bar -2- causes avcorresponding movement of the price pointer in the same direction alongthe scale of the price-bar 8 to show'that an increase or decrease in thedemand, as indicated by the demand-pointer on the scale-bar -2-,produces a corresponding increase or decrease in the price as indicatedby the pointer -24- on the price bar. For a similar purpose, the slide-27- of the price pointer -25- is attached to one end of an operatingcord or cable 33 having its intermediate portion passed over a sheave-34- on the upper cross bar -6- and its other end attached to thecorresponding end of theI goods bar 10 so end of the goods bar auditspointer llll in either direction along the supplyscale bar -3- producesa corresponding movement of the price pointer Q5- but in a reversedirection to show that the prices fall with an increased supply and risewhen the supply is decreased.

The raising and lowering of the demand and supply disks by means of thecords, therefore, represent the rise and fall of the demand and supplyof any goods or commodity which may be under consideration while theraising and lowering of the price pointers similarly represent the riseand fall of prices as produced by the variations in demand and supply,the pointers -13- and -14- coacting with their respective scale bars -2-and -3- to indicate quantitative variations while the pointers 24- and-25,-, coacting with their respective scale bars 8 and -9-, indicatedifferent prices of suchcommodities as produced by the fluctuatingquantitative values. These scales may be graduated and the apparatusadjusted so as to indicate absolute relations between varying degrees ofiuctuations in quantitative values of any commodity and prices producedby such variations but the apparatus is designed primarily to indicaterelative tendencies of quantitative and price values as aiected byvarious forces which tend to iniiuence the demand and supply as well asprices. In order that the relation of these forces to such commercialfactors as demand, supply and prices may be clearly illustrated, thedisks 11 and --12 are preferably made circular and of 130 relativelylarge diameter for receiving upon their perimeters a `series of clasps-35- adapted to retain one or more cards B6-.-

bearing suitable indicia representing the forces which would be liableto produce quantitative variations of any commodity which may be underdiscussion. These cards may be termed force cards and those whichrepresent forces tending to creplaced centrally on the outer edges ofthe same disks, lthereby showing at la glance the exact relations andeffects of Aany one or more of those forces upon the demand orsupply ofany selected commodity and through such variation of quantitative valueshows the relation between these forces and the varying prices of suchcommodity.'

The clasps -35- and cards supported thereby may be removed and replacedat will and in like manner the force cards may be removed and replacedfrom and upon the clasps and may be interchanged or substituted byothers at will, it'being understood that owing to the widely diversiedforces which might affect uantitative values, the cards may be classi edaccording-to their eii'ect upon such values.

For example, the cards, representing forces tending to increase thedemand, may be kept in one package while those tending to decrease thedemand may be kept in a separate package and, in like manner, the cardsrepresenting the forces which tend to increase and those which representany forces tending to decrease the supplypmay be kept in separatepackages ready for use in connection with the discussion oit therelation between demand, supply, prices and the various forces whichtend to iniuence them. I have also shown in the same apparatus means forillustrating the eiiect of variations in the demand, supply, values andprices of gold vupon the demand, supply, prices and price level of goodsand also the inverse relation or eEect in variations in demand, supply,-prices and price level -upon quantitative and price values of gold and,for this purpose have provided an additional ioating bar -40-, whichwill be termed the gold bar as extended transversely of and across theback of the upright scale bars and some distance beyond the outer edgesof the stationary bars -2- and -3 in a plane below the goods bar -10--,the outer ends ofthe gold bar bein provided respectively with a demanddis adjacent ends of the bar 40- and are provided with pointers -43- and4% mov- `able along and in proximity to the outer edges of the uprightdemand and supply bars '-2- and -3- as either end Vof the bar -40- israised or lowered in the manner presently described, said disks beingmaintained in substantially horizontal posit1ons by counterweights -46-similar to and operating in the same manner as the counterweights -19-for the disks .11-

The gold bar -40-, like the goods bars -10-, is centrally fulcrumed orpivoted at -47'- to a cross-head 4S- which like the cross head -16- isslidable vertically along and upon the middle' bar -Jland adjacentsliding vbars -8'- and -9-,. which in turn are guided in their verticalmovement in suitable ways in the cross head -48-- These disks -4=1` and42- also bear the abbreviations D. and S. respectively,indicatingvdemand and supply of gold and, like the disks A-lland -12f,are provided with suitable clasps -35- for receiving force cards -36-distributed around and upon the periphery thereof in a manner similar tothat described for the cards -36- on the disks .-11- and -l2 to indicatethe direction of influence which the forces marked on the cards mayexert upon the demand or supply of gold, the same description appliedto' the force cards for the goods bar being applicable to those for thegold bar except that the force cards forthe gold bar represent theforces which tend to influence the demand, supply, prices and value ofgold.

The floating lgold bar 40- is supported and manipulated bysuitable'cords or cables 50- and .-51- passing over separate Sets ofsheaves 452- and -53- on the upper cross bar -6- and having their outerends extending downwardly and attached to the oating bar -40- at or neartheir piv-` otal connections with the disks 41- and -42- and their innerends extending downwardly near the center of the apparatus and withineasy reaching distance of the operator where they Vmay be manipulated atwill either simultaneously or independently 4to lower and raise the baror either end of said bar together with the corresponding disk andpointer, the inner sheaves 532- and -53- being preferably of thegripping type to hold the cables and bar supported thereby in theiradjusted positions. Associated with this gold bar are separate goldvalue pointers -49- and -54- which are secured to suitable slides n-55-and '-56- and like the slides Q6-and -27- are movable lengthwise of andupon the stationi ary upright scale-bars -2- and -3-, the

free ends of the pointers being movable along the graduations on thegold-value bar -.-9-. These pointers may, therefore, be termedgold-value pointers and are adapted to be operated along the scale bar-9- simultaneously with the vertical movements of the correspondingendsof the gold bar or pointers -43- and 414- so as to indicate pricevariations simultaneously with quantitative variations in the demand orsupply of gold and for this purpose, are respectively connected tocorresponding ends of the gold bar by separate cords or cables -60- and-61. The cable 60- is attached at one end to the demand endA of the goldbar and extends downwardly around a sheave -62- on the lower cross bar-5- and thence upwardly over' a sheave #63- on the upper cross bar andthen downwardly to its point of attachment with the slide -55- so that,as the demand end of the gold bar is moved vertically in eitherdirection, the adjacent gold-value pointer ,-429- will becorrespondingly moved in the same direction to indicate that as thedemand for gold increases, there will be acorresponding increase in itsvalue. The cord or cable -61-, having one end attached to the slide -56-is passed upwardly over a sheave -65- on the upper cross bar -6- andthen downwardly and has its opposite end attached to the supply end ofthe gold bar 40- whereby, 'as the supply end of the gold baris raised orlowered, the slide -56- will be moved a corresponding distance but inthe reverse di'- rection along the gold value bars -9-, thus indicatingthat the value of gold increases with the increased supply and decreasesWith a reduced supply.

Anothervfeature of my invention lies in 4the means for showing therelation or interdependence of prices or price values of goods and goldvalues andfor this purpose, the price pointers Q4- and -25- or lrathertheir slides -`26- and -27- are connected by cords or cables and -71- tothe gold value bar -9-.

The cable -70- has one end attached toA a slide -26- and extendsdownwardly around a suitable sheave -72- on the lower cross bar -5- andthence upwardly around a sheave -73- on the upper cross bar -6 and thendownwardly to its point of attachnient with the gold-value bar -9-.

The cable 71- extends 'downwardlyy from its point of attachment to theslide -Q'-l around a suitable sheave -74- on the lower cross'bar 5'- andthence upwardly around a pair of sheaves -75- on the upper cross bar-6-,and then downwardly to its point of attachment to the gold-value bar---9-.H In a somewhat similar'manner, the gold-value pointers -49- and#-54- or rather-their slides-55- and y 56- are connected `by cords orcables the cord or cable being extended downwardly fromits point ofattachment to to its point of attachment to the price bar 7o i the slide-55- around a sheave -78- on f 1- i downwardly from itspoint ofattachment its'point of attachment tol the price bar Any one or more ofthe several cords previously described may be properly .adjustedor-tensioned by means of one or more clasps as -28-, Fig. 2,' to bringthe various parts operated thereby into properrelative adjustment, theconnections between said cords, bars and slides being easily detachablewhen necessary or desirable to illustrate the operation of anyindividual part of the device independentlyV of the other parts.

It is now clear that any vertical adjustment ofthe goods br l0- whichwill move either or both of the pointers -13- and 14- along the uprightscale bars -2- and -3- will-produce a corresponding vertical movement ofthe gold-value bar -9'- relatively tothe gold-value pointers -49- and5ato show that any force I which influences the general level of supplyand demand yor prices of goods, as indicated by the pointers y--13- and-14-,

and 2li-and -25-, also influences the value of gold as indicated by thepointers 4Q-.- and `-54-. and conversely the same part of the apparatusmay be used to illustrate that any force which iniiuences the value ofgold also affects the general level of quantitative values and prices ofgoods.

It is evident, however, that by disconnecting the cordsor cables -70-and 71- from their respective slides -26- `and 27-, the apparatus may beused to indicate simply the variations in prices or price .nected in themanner described, the price pointers 2L and -25- may be ignored and therelation between variations inthe supply and demand of goods and goldvalues and the forces which influence'thesafactors may be clearlydemonstrated.' In asimilar manner, the vertical adjustment of the goldbar -40- .and corresponding pointers -43- and -44- along the scale bars,-2-

. -56- to show that any forces represented by the force cards on thedemand and supply disks of the gold bar'which may effectgold values asindicated by the pointers -49- and -54- will influence price levels ofgoods as indicated -by the movement of the price bar -8-- relatively tothe price pointers 2liand -25- and conversely the vertical adjustment ofthe price bar -8- will produce a corresponding adjustment of thegold-value pointers 49- and -54- and also the gold bar -40- to indicatethe effect of the adjustment of the price bar on supply and demand ofgold as represented by the gold pointers -43- and -44-.

It is evident, however, that the cords 76- and -7 7 may be disconnectedfrom their respective slides -55- and -56- and the gold-value pointers4Q- and 5tused independently in connection with the gold bar to indicatethe effect of certain forces acting upon .the supply and demand of goldupon gold values.

As previously stated, the marginal cost bar -4- is adjustable verticallyrelatively to and independently of the price bar 8- and gold-value bar-9- and, therefore, relatively to the price `pointers and goldvaluepointers to conform to a change of position of the gold-value andprice-bars relative to the demand and supply bars, due to changes in thevalue of gold and general price levels, which in turn are due to changesin demand and supply and their underlying forces.

The demand and supply disks on the gold bar -40- are similar to thedisks l1- and l2- on the goods bar -and are equipped with suitableclasps -35-- for receiving force cards -36- upon which are printed orotherwise impressed indicia of forces which affect the demand and supplyof gold, said force cards being placed upon their respective disks inthe manner previously described in reference to the force cards'on thedisks of the goods bar according to the direction of influence exertedby such forces uponquantitative gold values and prices of gold.

The cords -30- and -33- and also the cords -60- and -61- are attached toslidingl members -90- which are adjustable lengthwise of and upon theirrespective bars l0- and L10- to aiford a wider variation in the relativedegrees of movement of the pointers and movable scale bars in accordancewith the varying degrees of elasticity of demand and supply and othervarying conditions which may require such adjustment.

The apparatus shown and described is 4 particularly valuable from apedagogical point of view in demonstratin the causal and functionalrelations existing between demands, supplies, costs and prices of goods;between the demands, supplies, costs and prices of gold; between valuesof gold and both particular Iprices and `.general Eprice levels ofgoods, and between all of those factors and the fundamental facts andforces operating through demands and supplies to X'eXchange values butit is evident that these various relations may be clearly demonstratedin a general way without the use of either the Xed or sliding scales andthat certain of the specificv relations referred to may be demonstratedby parts of the apparatus irrespective of other parts.

It is also evident that various changes may be made in the structuraldetails of the apparatus without departing from the spirit of myinvention and, therefore, I do not `limit myself to the precisestructure shown and described.

Vhat I claim is:

1. In an educational appliance for teaching economics, an upright scalerepresenting quantitative variations, and a holder movable along thescale bar and bearing indicia representing forces which cause suchvariations. y

2. An educational appliance having an upright scale-bar graduated torepresent quantitative variations, a transversely eX- tending barmovable along the scale-bar, a disk pivoted to said bar and providedwith arpointer movable along the scale-bar, and force cards mounted onthe disk and bearing indicia representing forces which influencequantitative values.

An educational appliance comprising an upright scale-bar having a scaleof marginal costs, a separate scale-bar having a scale of prices, saidbars being movable relatively to each other, and a pointer movable alongthe scales of both bars.

4. An educational. appliance comprising an upright scale-bar having a,scale of quantitative values, a separate upright bar having a scale ofmarginal costs, and separate pointers movable along their respectivescales.

5. An educational appliance having a Ascale of quantitative values, apointer mov- IOL tel-+5,11:educational-7519 Plance -havg al scale ofquantitative va ues, a pointer' movable along said scale, a-separatescale movable relatively :to the first named scale, and

connections between said pointer and movtingmotion from one pointer tothe other.

. for the price scale. 35

ing scales indicatin 8. In afmechanical appliance kfor teachineconomics, ascale of vquantitative deman values; a separate scale ofprice values, separate pointers movable along said scales, and means fortransmitting motion from one pointer. to the other. v

l9,1111 a mechanical appliance for teaching economics, a scale ofquantitative supply values, a separate scale of'price values, separatepointers movable along said scales, and means for transmitting motionfrom one pointer to the other.

10. In a mechanical appliance for teaching economics, separate scalesindicating,v respectively, quantitative demandvalues and quantitativesupply values, a third scale indicating price, values, separate pointersmovable along said scales, means for moving the pointers forv thequantitative scales simultaneously, and means for transmitting motionfrom one of said pointers to the pointer l1. In a mechanical appliancefor teaching economics, a pair of upright bars having quantitativedemand andsupply scales, respectively, a separate upright bar having aprice scale, pointers movable along the quantitative scales, additionalpointers movable along the price scale, separate devices for moving thepointers for the quantitative scales,'simultaneously or independently ofeach other, and additional devices for transmitting motion from the lastnamed pointers tov the pointers for the price scale.

12. In a mechanical appliance for teaching economics, a pair of uprightbars having quantitative scales representing demand and supply values,respectively, an additional upright bar having` a scale of price values,a cross bar movable vertically along the irst-named bars, means foroperating the cross bar, a pointer movable along the scale on the ricebar, and means for transmitting motlon from the cross bar to saidpointer.

, 13. In 'a mechanical appliance for teaching economics, a pair ofupright bars havquantitative values of supply and deman respectively, across bar movable vertically along said bars, separate devices ,forraising and lowering either end lof the `cross bar independently of theother end, an additional upright bar having escalel of price-values,separate-pointers -movable along the price scale, and means fortransmitting to said pointers. ,i

motion f from the cross bar 14. In a mechanical appliance for .teachingeconomics, a scale, representing quantitative values, an indicatormovable alon said scale, members mounted on the indlcator `bearingindicia of forces-which, influence such quantitative values, a separatescale indicating price values, an indicator movable along the pricescale, andmeans for transmitting motion from onel indicator to theother. i

15. Inal mechanical appliance for-teaching economics, a scalerepresenting quantitative values, -a separate scaleV representing goldvalues and adjustable lengthwise of the first-named scale, an indicatormovable along the quantitative scale, means for transmitting motion fromsaid indicator to the gold value scale, and a separate indicaj 'tor forthe last-named scale.

16. In a mechanical appliance for teaching economics, an upright barhaving a scale representing quantitative values, an indicator movablealong said scale, operating means for said indicator, an additionalupright bar movable vertically and provided with a scale representinggold values, an indicator for the'gold value scale, and means for movingthe gold value bar simultaneously with the movement of the firstnamedindicator. l l

17. In amechanical appliance forteaching economics, an upright barhaving ascalc. representing quantitative values, a separate upright barhaving a scale of price values, separate indicators movable along theirrespective scales, a vertically movable upright bar having ascalerepresenting gold values, means for operating the indicators andgold value bar simultaneously, and means for in- .dicating the degree ofadjustment of the gold value bar. g 1:8. In a mechanical appliancefor'teaching economics, an upright bar having a scale representingquantitative values, a vertically adjustable upright bar having. a scalerepresenting price values, an indicator movable along the quantitativescale, means for moving said indicator and price bar simultaneously,`andmeans for indicating the degree of adjustment of the price bar.

19. In a mechanical appliance for teaching economicsfan upright barhaving a scale representing quantitative values, an additional uprightbar having a scale representing gold values, indicators movable alongsaid scales, a vertically adjustable upright bar having a scalerepresenting price values,

20. In a mechanical appliance for teaching economics, an upright barhaving a scale representing.quantitatlve values, an indicator movablealong said scale, a separate upright bar having a scale representinggold values, an indicator movable along the gold value scale, and meansfor operating the indicators simultaneously.

21. In a mechanical appliance for teaching economics, an upright barhaving a scale representing quantitative values, an indicator movablealong said scale, members mounted on the indicators and bearing indiciarepresenting forces Which"influence quantitative values, a separateupright bar having a scale representing gold values, an

indicator movable along the gold value scale, and means for moving theindicators simultaneously. y

22. In a mechanical appliance for teaching economics, an upright barhaving a scale representing quantitative values, a separate upright barhaving a scale representing price values, an additional upright baradjustable lengthwise of the price bar and provided With a scalerepresentingmargnal cost values, means for clamping the marginal costbar in its adjusted position, indicators movable along said scales, andmeans for operating the indicators simultaneously. 23. In a mechanicalappliance for teaching economics, the combination of a frame having apair of upright bars provided with sca-les representing, respectively,quantitative demand values and quantitative supply values, an additionalpair of upright bars having scales representing, respectively,

price values of goods and gold values, sepa-

